Safety device



March 31, 1931- J. J. EHEMANN, sR., ET AL 1,798,318

SAFETY DEVICE Filed March 23, 1929 2 Sheets-Sheet 1 March 1931- J. J. EHEMANN, sR., ET AL 3 SAFETY DEVICE Fi led March 25, 1929 2 Sheets-Sheet 2 Patented Mar. 31,- 1931 PATENT OFFICE UNITED STATES JOSEPH J. EEEMANN, 83., AND BENJAMIN I. SING OI LANCASTER, PENNSYLVANIA.

SAFETY DEVICE Application filed Iarch 28, 1829. Serial No. 849,475.

This invention is a safet upon automobiles and its ob ect is to provide a device which will automatically arrest the movement of the vehicle if it should start to l travel backward on, a down grade. It is the habit with motorists to take all grades in high gear to avoid the labor of shifting gears and it frequently happens that the machine stalls before the top of the hill has been reached and, unless the chauffeur is adept at shifting gears, the machine will travel backward some little distance before its progress can be stopped. N umerousbad accidents have occurred through the lack of means to instantly stop the rearward travel oft-he machine, and the object of the present invention specifically stated is to provide means which n will automatically operate to prevent reverse travel of the vehicle on a down grade. invention provides means whereby when the reverse travel of the machine is desired the safety device will be thrown into inoperative position and will then not interfere with'the desired travel until the gears have been shifted to again provide for forward travel.

The invention is illustrated in the accompanying drawings and will be hereinafter first fully described and then more particularly defined in the appended claims.

,In the annexed drawings:

Figure 1 is a sectional elevation showing one embodiment of the invention mounted within the transmission case of the vehicle and applied to the motor shaft,

Fig. 2 is an enlarged sectional elevation taken longitudinally of the. shaft,

Figs. .3 and 4 are elevations showing the operative and inoperative positions of the device,

Fig. 5 is a detail perspective viewof the clutch hub, and

Fig. 6 is a detail perspective view of the roller or dog manipulating element.

In the drawings, the reference numeral 1 indicates the motor casing, the reference numeral 2 indicates the transmission casing and the numeral 3 indicates the gear shifting lever, all of which are of the usual or any approved construction. Within the transdevice for use The.

mission casing 2 are mounted the usual or any approved transmission gearing 4 where-.

' by the power of the engine may be imparte to the propeller shaft 5 at the desired speed and in the desired direction. The lever 3 cooperates with shifter rods 6 and selector arms 7 in a well known manner to set the gear- .ing for the transmission of the desired speed.

Secured to the rear wall of the transmission case and a hub 10 which is keyed to the shaft, as will be understood upon reference to Fig.

2. The hub 10 is provided in its peripheral surface with a plurality of recesses or chambers 11 in each of which is disposed one of the rollers or free dogs 9 and said recesses or chambers are right angular in form andcooperate with the wall of the casing to form a triangular s ace within which the res tive rollers or ee dogs 0 crate. A cap p i e 12 is secured upon the fbrward side of the casing 8 and extends inwardly be 0nd the inner wall thereof, as shown in ig. 2, so

that it projects over the rollers and thereby prevents the escape of the same. The hub 10 is provided between each two recesses with a lug or projection 13 against which the cap plate rests and in the space thus defined under the cap plate are mounted a plurality of cranks or do shifting elements 14 which are pivotally tted to the hub and are adapted to be operated to throw the rollers or dogs into an inoperative position. The cranks 14 are substantially oblong in outline and are pivoted upon the hub near their inner ends by means of pins or studs 15 which are welded or otherwise intimately united with the respective cranks and are adapted to seat in sockets 16 provided'therefor in the hub. At the inner end of the crank is secured an operating pin 17 which projects outwardly be integral with or ri spective roller 9 and thereby control the same, it being understood that e portion of the circumference of the roller will project beyond the crank and the holder to ride upon the wall of the case 8. The several pins 17 have their outer free ends engaged in notches or elongated openings 19 in a ring 20 which may 'dly secured to one end of a sleeve 21 slida ly mounted upon the shaft 5 and provided at its o%posite endwith an annular groove 22 in w ich is enga ed one of the selector yokes '2'. An obliquely isposed slot 23 is formed invthe sleeve 21 and through this slot projects'a pin or stud 24 secured in the shaft 5, as will he understood.

lit will be understood that the casing 8, being fined to the transmission casing, is stationery at all times and the hub 16, being keyed to the shaft 5, will alweys rotate with the shaft, Qrdinarily the rollers will be held in a position out of contact with the walls of the recesses 11 through the influence of an expensien spring 25 which is coiled around the shaft 5 between the huh it) the ring or e 2G en end presses said and sleeve forward. Should the for-. ward. travel of the machine stop, the die vice will not be affected unless the machine should at ence commence to travel basi ereupen the reverse travel". it 5 evi carry e the obliquely or 1 :y d oil the recesses he hre s 9 and th i carry he sele tor L e roove .22, the will he slid re enee of the spring ed rearwardly, 6

en the stud me about the shaft s3 is engegcnien .I. x. th .e 20 so that itwardly and Q. epexes oi the sevs 11 and the rollers H, shifted toward Jider ehmnhers. e rollers consequently, he held out 0i cont-set with the of chambers and the travel oi the machine then he effected and controlled just though the sefety device wee not present. As the reverse gear is shifted to its normal position the ring 25 expand end act to maintain the safety device to its normel weenie ogeretive position. When the sleeve 21 s 'fted forwerdly, it is rotated about she-ft 5 by the engagement of the in 24 and the cam slot 23 so that thecra will he ruched in such direction that the rollers are shifted to a osition free of the walls of the respective c ambers. The strength of the spr1ng25 is such that it will just hold the rollers in neutral position and maintain such frictional engagement between the pin 24 and the cam slot 23 that the sleeve 21 will rotate with the shaft without sliding along the same but if the shaft should" start to reverse the pin and cam slot will act on the sleeve in the same direction as the spring to shift the rollers toward and ermit them to assume the braiding" position. en the machine is thrown in reverse, the rollers are locked in the ineperetivo position against an tendency of the spring to shift them towar braking position.

. From the fore oing description, taken connection with t e accompanying drawings, it will he seen that we have provided an ez:-- ceedingly simple and e which may be applied t e, low cost to any vehieie and will ope L303 nutcmatically to prevent undesired he elm" travel of the ve hiclei in applying e invention to vehiclec cou se product n, the ones 8 and Will i w .1

cireut Tier d e ere h; i y upon the hub provided its f holder engaginw the toilet a pin p from the opposite end cf the cre sli Jhly rotatably mounted for shifting the sleeve said sleeve having i v pin is seated whereby ts rock the c1.

shiit the roller to en inoperetive p sit f yieldehle means acting on the sleeve to nermelly hold the same end roller in an. eperative position.

2w in a safety device the cemhinetion of circular ease, nieens for seenrin the I 1 I u ststionarily snout a shaft, s huhseeured upon the shaft within the case and provided in its periphery with a tapered recess formin with the wall of the case a triangular cham er, a free roller in said chamber, a crank pivoted eccentrically upon the side of the hub and engaged at its free end with the roller, a in prejectin laterally from the opposite en of the era a sleeve slidably and turnably mounted upon the shaft, a ring carried by one end of the sleeve and engaged with the pin projecting from the crank, the sleeve bemg provided with a diagonal slot, a stud on the shaft en aged in. sald slot, means for shifting the s eevetoward the hub, and an expansion s gring disposed between the ring and the hu to yieldably hold the crank and the roller normally in an operative position.

In testimony whereof we aflix our signatures.

JOSEPH J. EHEMANN, SR. BENJAMIN F. SINGER; 

